[partition] Prepare for swap options

- Extend PrettyRadioButton with options (combo-boxes which may
   be added later).

src/modules/partition/gui/PrettyRadioButton.cpp

@@ -21,15 +21,16 @@
 #include "utils/CalamaresUtilsGui.h"
 #include "widgets/ClickableLabel.h"
 
+#include <QComboBox>
+#include <QGridLayout>
 #include <QLabel>
-#include <QBoxLayout>
 
 
 PrettyRadioButton::PrettyRadioButton( QWidget* parent )
     : QWidget( parent )
 {
-    QHBoxLayout* mainLayout = new QHBoxLayout;
-    setLayout( mainLayout );
+    m_mainLayout = new QGridLayout;
+    setLayout( m_mainLayout );
 
     m_radio = new QRadioButton;
     m_label = new ClickableLabel;
@@ -41,9 +42,9 @@ PrettyRadioButton::PrettyRadioButton( QWidget* parent )
     m_label->setWordWrap( true );
     m_label->setSizePolicy( QSizePolicy::Expanding, QSizePolicy::Preferred );
 
-    mainLayout->addWidget( m_radio );
-    mainLayout->addWidget( m_label );
-    mainLayout->setContentsMargins( 0, 0, 0, 0 );
+    m_mainLayout->addWidget( m_radio, 0, 0 );
+    m_mainLayout->addWidget( m_label, 0, 1, -1, 1 );  // Row span to right edge
+    m_mainLayout->setContentsMargins( 0, 0, 0, 0 );
 }
 
 
@@ -80,3 +81,11 @@ PrettyRadioButton::buttonWidget() const
 {
     return m_radio;
 }
+
+void
+PrettyRadioButton::addOptionsComboBox( const QString& label, QComboBox* box )
+{
+    int row = m_mainLayout->rowCount();  // Rows index from 0, count from 1
+    m_mainLayout->addWidget( new QLabel( label ), row, 1 );
+    m_mainLayout->addWidget( box, row, 2 );
+}

src/modules/partition/gui/PrettyRadioButton.h

@@ -22,7 +22,16 @@
 #include <QRadioButton>
 
 class ClickableLabel;
+class QComboBox;
+class QGridLayout;
 
+/** @brief A radio button with fancy label next to it.
+ *
+ * The radio button itself can be retrieved with buttonWidget(),
+ * and the whole behaves a lot like a label. Extra options can be
+ * added to the display (options are hidden when the button is
+ * not selected) with addOptionsComboBox().
+ */
 class PrettyRadioButton : public QWidget
 {
     Q_OBJECT
@@ -40,9 +49,13 @@ public:
 
     virtual QRadioButton* buttonWidget() const;
 
+    /** @brief Add an options drop-down to this button. */
+    void addOptionsComboBox( const QString& label, QComboBox* );
+
 protected:
     ClickableLabel* m_label;
     QRadioButton* m_radio;
+    QGridLayout* m_mainLayout;
 };
 
 #endif // PRETTYRADIOBUTTON_H